The present invention relates to an electromagnetic power supply and in particular to an electrical power generator intended for installation within a vehicular tire. Such electrical power generator can supply electrical power to energize a pressure sensor and a high frequency radio transmitter for monitoring tire air-pressure while traveling. Incorrect low tire pressure may cause, while traveling, tire rupture and an accident.
A system for generating electrical power utilizing ferrofluid is described in U.S. Pat. No. 4,064,409, by Charles M. Redman. Thermal energy is converted into electrical power using flow of magnetized ferrofluid through a coil. An additional system utilizing ferrofluid and a permanent magnet is described in U.S. Pat. No. 5,632,093 by Sharon A. Elias, where mechanical vibrations are converted into an electrical voltage.
The ferrofluidic, electromagnetic power supply constructed in accordance with the principles of the present invention consists of: a sealed housing made of non-magnetic material partially filled with ferrofluid ; a flat electrical coil wound of insulated, electrically conductive wire firmly attached to a flat part of said housing; a cylindrical -section permanent magnet axially polarized firmly attached to the other flat side of said coil. A magnetic circuit is formed extending from said ferrofluid through said coil to said permanent magnet and back to said ferrofluid. Agitation of the power supply will cause dislocation of said ferrofluid, and therefore, induction in the electrical coil.
In view of the above it is the principal object of the present invention to provide an electromagnetic power supply to power a pressure sensor and radio transmitter for the purpose of monitoring air pressure within the tire while the vehicle is in motion.
A still further object of the present invention is to provide such a device that has the capability to generate electrical power when firmly attached to an agitating object.
A further object is to provide such a device which may be small in size reliable, with no movable solid mechanical components.
A still further object is to provide such a device, which is simple in design and easy to manufacture. The above objects and advantages are attained with the present invention by providing two embodiments of a ferrofluidic, electromagnetic power supply.